Backup Strategies

Most backup methods use the archive bit on a file to identify files that need to be backed up.When a file is modified, the system automatically flags the file as needing to be archived. When the file is backed up, the backup method may reset (clear) the archive bit to indicate it has been backed up.

Full Backup - Backs up all files regardless of the archive bit. + Resets Archive Bit.
Incremental Backup - Backs up files on which the archive bit is set. + Resets Archive Bit.
Differential Backup - Backs up files on which the archived bit is set. + doesn't reset Archive Bit.
Copy Backup - Backs up all files regardless of the archive bit status. + doesn't reset Archive Bit.

Most of the time, you will perform backups using a strategy that combines backup types.

Full Backup - Requires large tapes for each backup.Takes a long time to perform each backup. If you want to restore it,restore only the last backup.
Full + Incremental - Incremental backups are quick to perform. This is the fastest backup method.If you want to restore,restore the full backup and every subsequent incremental backup.
Full + Differential - Differential backups take progressively longer to complete as time elapses since the last full backup. If you want to restore,restore the last full backup and the last differential backup.Next to a full backup, this is the fastest restore method.

Some Facts:
-Back up user data more often than system state data (it changes more frequently).
-Back up system state data whenever you make a system change.
-System state data includes the registry, COM+ Class Registration database, system files, boot files, files under Windows File Protection, and the Certificate Services database.
-During a system data backup, all system data is backed up (system data cannot be backed up selectively in portions).
-Files backed up from one system might not restore to another system. Restore to a system running the same OS.
-Be sure to test your back up and restore strategy. It does no good to back up your data if you can't restore it.
-A normal Directory Services restore refers to a process wherein you restart the domain controller in Directory Services Restore Mode and restore system state data.
-Using the Services snap-in, Windows Backup, or the Scheduled Tasks window, you can start the Task Scheduler service. You must have the Task Scheduler service running before you can schedule a backup.
-In order for a scheduled task to run, you must specify a local service account and password.